Levin argues that human-caused global warming is nothing to worry about, and merely an excuse for the Enviro-Statists (capitalization in the original) to seize more power. It reads like a bunch of pasted-together quotes and stories based on some quick Google searches by somebody who knows very little about the topic, and can’t be bothered to learn. After pages devoted to talking about prior global cooling fears, and some ridiculous or cynical comments by advocates for emissions restrictions (and one quote from Richard Lindzen, a very serious climate scientist who disputes the estimated magnitude of the greenhouse effect, but not its existence), he gets to the key question on page 184 (eBook edition):

[D]oes carbon dioxide actually affect temperature levels?

Levin does not attempt to answer this question by making a fundamental argument that proceeds from evidence available for common inspection through a defined line of logic to a scientific view. Instead, he argues from authority by citing experts who believe that the answer to this question is pretty much no. Who are they? An associate professor of astrophysics, a geologist, and an astronaut.

But he says that these are just examples:

There are so many experts who reject the notion of man-made global warming and the historical claims about carbon dioxide they are too numerous to list here.

He goes on to cite a petition “rejecting the theory of human-caused global warming” sponsored by the Oregon Institute of Science and Medicine and signed by more than 31,000 scientists. There are a few problems with this survey that Levin doesn’t mention. More than 20,000 of these “scientists” lack PhDs in any field. There was very little quality control: At least one person signed it as Spice Girl Geri Halliwell. Scientific American did the hard work of actually contacting a sample of individual signatories, and estimated that there are about 200 climate scientists who agree with the statement in the petition among the signatories. And most important by far, the text of the petition is not close to Levin’s claim of rejecting the notion of man-made global warming. In the key sentence it says that signatories do not believe that there is compelling scientific evidence that human release of greenhouse gases will cause catastrophic heating and disruption of the earth’s climate. Depending on the definition of “catastrophic,” I could agree to that. Yet I don’t reject the notion of man-made global warming.

On one side of the scale of Levin’s argument from authority, then, we have three scientists speaking outside their areas of central expertise, plus a dodgy petition. What’s on the other side of the scale that Levin doesn’t mention to his readers?

Among the organizations that don’t reject the notion of man-made global warming are: the U.S. National Academy of Sciences; The Royal Society; the national science academies of Australia, Belgium, Brazil, Canada, China, France, Germany, Ireland, Italy, India, Japan, Mexico, New Zealand. Russia, South Africa, and Sweden; the U.S. National Research Council; the American Association for the Advancement of Science; the American Chemical Society; the American Physical Society; the American Geophysical Union; and the World Meteorological Organization. That is, Levin’s argument from authority is empty.

Of course, this roll call could be arbitrarily long and illustrious, and that does not make them right. Groupthink or corruption is always possible, and maybe the entire global scientific establishment is wrong. Does he think that these various scientists are somehow unaware that Newsweek had an article on global cooling in the 1970s? Or are they aware of the evidence in his book, but are too trapped by their assumptions to be able to incorporate this data rationally? Or does he believe that the whole thing is a con in which thousands of scientists have colluded across decades and continents to fool such gullible naifs as the U.S. Congressional Budget Office, numerous White House science advisors, Margaret Thatcher, and so on? Are the Queen of England and the Trilateral Commission in on it too?

But what evidence does Levin present for any of this amazing incompetence or conspiracy beyond that already cited? None. He simply moves on to criticisms of proposed solutions. This is wingnuttery.

Manzi’s critique is not just poorly reasoned; : it’s ironic. Manzi flogs Levin for not citing enough experts: : –: : but of course, the rockstar of the manmade global warming movement is Al Gore, who is of course, no scientist. Then, like many believers in manmade global warming, Manzi tries to dismiss the 31,000 scientists who are willing to shoot holes in his pet theory. See, when your whole theory is based on the idea that everyone agrees with it, having more than 30,000 scientists saying, “We don’t buy it,” is a huge problem. Moreover, after kvetching that Levin didn’t spend enough time on the science behind global warming, Manzi provides — you guessed it, zero scientific evidence that backs his position.

In fact, that gets down to the nub of the problem: the evidence global warming alarmists present for their position is always circular. Why is man causing dangerous global warming? Because there’s a scientific consensus that’s the case. Can any of these scientists explain: their reasoning in a way that answers the most basic questions about their theory? No. None of them can do it. I’ve written a dozen plus posts on this subject. I’ve written columns about it.: : I ‘ve literally read hundreds of posts from the Right, Left, and in-between on the subject and I’ve never, not one single time, seen ANYONE, scientist or otherwise, who could give convincing answers to even the basic questions people have about the theory of manmade global warming. They don’t even try. They just say, well, : it’s “scientific consensus.”

So, in essence, we have a bunch of people, including scientists, saying “We don’t know why we believe what we believe, but more of us believe it, so it must be true.” But, if there’s no actual science that makes sense behind the scientific consensus, what good is it?

You know why I don’t buy that man is causing global warming — or: that there’s even any global warming going on? It’s because every plausible scientific argument I’ve ever heard has come from people shooting holes in the theory. If Al Gore, Jim Manzi, and the rest of the “We’re all going to die because of global warming crowd” can ever come up with some credible scientific arguments to support their position, which they keep insisting is based entirely on science, I’d be willing to be convinced. Most skeptics of manmade global warming would probably feel the same way. But in a post-Climategate world they simply can’t say “more scientists agree with our position; : so therefore we must be right” and expect people to fall into line.